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Biomedical subjects

M Kuboki

Publications and source records attributed to M Kuboki.

35 records · Page 2Linked to original sources
PubMed1984

The effect of plasma on platelet function in hypercholesterolemic rabbits and the changes in fatty acid composition of the plasma.

Rabbits were fed with 1% cholesterol-containing standard diet for 1 to 3 months. The arachidonic acid (AA)-induced aggregation of the platelet-rich plasma (PRP) of the control rabbits was accelerated by substitution of hypercholesterolemic plasma. The incorporation of 14C-AA into thromboxane B2 in platelets was increased approximately 1.6 times with PRP and 1.2 times with the washed platelet suspension (WPS) in hypercholesterolemic rabbits as compared with those of the control. Analysis of the fatty acid compositions of phospholipids and total lipids of hypercholesterolemic rabbits revealed an increase in AA of platelets and plasma, and a decrease in docosahexaenoic acid (DHA) in plasma. The AA/DHA ratio of plasma increased dependently on the period of feeding with the high cholesterol diet, and the increase in the ratio was parallel with the acceleration of platelet aggregation by AA in PRP.

Animals↗
PubMed1984

[Prognostic significance of the initial clinical findings in patients over 40 years of age with secundum atrial septal defect].

Controversy concerning medical versus surgical management of elderly patients with secundum atrial septal defect (ASD II) remains unsolved. To clarify this problem, we studied relation between initial clinical findings and long-term prognosis of patients with isolated ASD II over 40 years of age. Of 47 patients medically managed, 13 patients died during the follow-up period. Among these, 11 died of congestive heart failure (CHF), and 2 died of non-cardiac disease. Mean age and follow-up period of these 11 were 68.1 +/- 9.0 and 6.7 +/- 5.1 years, respectively, and those of 34 survivors were 61.9 +/- 7.5 and 7.7 +/- 5.8 years, respectively. All 6 patients of functional capacity III-IV (NYHA classification), and 5 of NYHA II, died. Seven patients of NYHA II progressed to NYHA III-IV, and the other 20 of NYHA II and all 7 patients of NYHA I remained unchanged during the follow-up. Overt CHF (p less than 0.001), mitral and/or tricuspid regurgitation (p less than 0.01), combination with arterial hypertension and/or ischemic heart disease (p less than 0.05), atrial fibrillation (p less than 0.01), P-sinistrocardiale (p less than 0.001), and R/S (V6) less than 2.0 (p less than 0.01), cardiothoracic ratio greater than 55% (p less than 0.001), width of right descending branch of the pulmonary artery greater than 25 mm (p less than 0.01), and mitral valve prolapse in the echocardiogram (p less than 0.05) were significantly frequent in the cases clinical deterioration. Of 32 patients, whose functional capacities were NYHA II initially, 12 showed progression and 20 were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Coronary angiographic findings in various types of unstable angina--study on the pathophysiology of unstable angina.

Coronary angiographic findings were studied in 129 patients with various types of unstable angina in order to clarify the pathophysiology of unstable angina. The subjects were divided into 3 types: effort angina (E), rest angina (R), and effort and rest angina (E+R), and each of these 3 types was subdivided into group I (new onset), II (recurrent) and III (changing pattern). 1) R had less severe coronary lesions than E or E+R. 2) Severity and distribution of coronary atherosclerotic lesions in unstable angina were similar to those in stable angina. 3) Incidence of coronary spasm is higher in unstable R and E+R than in stable R and E+R, respectively. 4) Unstable R and E+R with frequent attacks were associated with a higher frequency of coronary spasm and severe proximal coronary stenosis than those without frequent attacks, respectively. 5) Among unstable E+R-III (changing pattern), the patients who developed E+R from E showed significantly higher incidence of multiple vessel disease than those who developed E+R from R and significantly lower incidence of spontaneous spasm than those with E+R, who remained with the same pattern but in whom the frequency and/or the intensity of the attack increased, without any significant difference in the severity of coronary stenosis from other 2 subgroups. It is concluded that coronary spasm as well as severe coronary atherosclerotic lesions may be responsible for the unstable state of angina. Especially in R and E+R, coronary spasm is the most important factor responsible for the unstabilization of angina.

Adult↗
PubMed1982

Evaluation of the left ventricular function in aortic regurgitation by echocardiography and indicator dilution method.

The left ventricular function and severity of LV volume overload were assessed in 30 patients with aortic regurgitation by a combined use of echocardiography and indicator dilution method. With decreasing functional capacity of patients, there tended to be greater increase in EDV, and decreases in CO, EF, Vcf, and BAP(DN)/ESV, and shift of LV function curve downward and to the right, reflecting LV myocardial dysfunction. There was a substantial correlation between functional capacity and the severity of regurgitation as well as LV myocardial function, suggesting the possibility that clinical symptoms may depend upon both the myocardial function and severity of aortic regurgitation. In contrast with many patients with AR of functional class I or II, who had relatively normal LV function, the patients of class III consistently showed substantial LV myocardial dysfunction. After sublingual administration of ISDN, BAP lowered, EDV and RF decreased. Lowering of BAP and RF were more prominent in class III than in class I. It has been proved that a combined use of echocardiography and indicator dilution method is of value in assessing the left ventricular function and regurgitant fraction in patients with aortic regurgitation, allowing a better understanding of the disease process and the potential for recognizing patients who may require early valve replacement.

Aged↗
PubMed1982

[Evaluation of regional wall motion of the left ventricle before and after nitroglycerin administration in patients with ischemic heart disease: comparison between two-dimensional echocardiograms and coronary angiograms].

Effects of nitroglycerin (NTG) on segmental wall motion and pump function of the left ventricle (LV) were studied in 19 patients with ischemic heart disease (IHD) and 10 normal controls by two-dimensional echocardiography (2DE) and coronary arteriography (CAG). Short-axis cross-sectional images of the LV at the mitral valve, papillary muscles and the apex were recorded and subdivided into quadrants at each level. The center of gravity of the end-diastolic LV cavity and the axis intersecting this point and the right side of the posterior end of the interventricular septum were used as the reference point and line. The areas of whole sections and of each quadrant at end-diastole (Ad) and end-systole (As) were measured by the computer. Regional contractility and pump function of the LV were evaluated by (Ad-As)/Ad and (Ad-As) of quadrants and sections. The results were as follows: Blood pressure (BP), Ad and (Ad-As) of sections significantly decreased after NTG administration. (Ad-As)/Ad of the sections with normal wall motion showed no significant change after NTG. (Ad-As)/Ad of the quadrants with hypokinetic segmental wall motion showed a tendency to increase after NTG in contrast with the normal quadrants which showed no significant change. CAG findings and hemodynamic parameters in patients who showed a significant increase in (Ad-As)/Ad of all sections after NTG (Gr. I) were compared with those in patients who showed a decrease in (Ad-As)/Ad of all sections (Gr. II). There was no significant correlation between CAG findings in Gr. I and Gr. II. The only difference between these two groups before NTG was that mean Ad of sections in Gr. I was significantly greater than that of Gr. II. After NTG, Gr. I showed a significant decrease of BP, but Gr. II did not show any significant change. (Ad-As) of sections in Gr. I increased or showed no change after NTG, but those in Gr. II decreased. In conclusion, NTG can reverse wall motion asynergy, especially in hypokinetic segments, and produce favorable changes in pump function in patients with increased Ad before NTG. The mechanism of NTG to improve wall motion and pump function is considered to be afterload and preload reduction.

Blood Pressure↗
PubMed1982

[Computer analysis of wo-dimensional echocardiogram for the quantitative evaluation of left ventricular asynergy in myocardial infarction].

Quantitative assessment of left ventricular asynergy in myocardial infarction was made by computer analysis of the two-dimensional echocardiogram. Short-axis cross-sectional images of the left ventricle at the levels of the mitral valve, papillary muscle and apex were recorded by a phased array sector scanner in 20 patients with myocardial infarction and ten normal controls. End cardial and epicardial outlines at end-diastole and end-systole were traced and analyzed by a computer system. Short-axis cross-sectional images of the left ventricle were divided equally into octants and analyzed with a fixed external reference system, using the center of gravity of end-diastolic left ventricular cavity and the axis intersecting this and the right side of the posterior interventricular septum as the reference point and line. Segmental hemiaxis, area, wall thickness and those changes during cardiac cycle were measured and calculated in each octants. Regional contractility of the left ventricle was evaluated by systolic percent change of segmental hemiaxis, area and wall thickness. These parameters were significantly reduced in the infarcted segments documented by left ventriculography and electrocardiography. The area method is better than the hemiaxis system in both reproducibility and variability. The center of gravity of the left ventricular cavity determined by the computer shifted slightly towards the anterior wall during systole in normal subjects, possibly reflecting anterior swinging motion of the entire heart. The center of the gravity of the left ventricular cavity in myocardial infarction showed the tendency to shift towards the infarcted region, suggesting the possibility that the location of asynergic area can be detected by determining the direction of the gravity center shift during systole in patients with a single infarction. This finding gives a basis of using the fixed reference system for the detection of asynergy. The use of computers for the analysis of short-axis two-dimensional echocardiographic images is very useful for the quantification of regional contractility of the left ventricle in a clinical setting.

Computers↗
PubMed1981

Handgrip-induced negative U-wave in electrocardiogram of hypertensive subjects.

To study clinical significance and possible mechanism of negative U-wave observed in hypertensive patients, we applied handgrip test (HG) to 35 patients with hypertension and 20 age-matched normal subjects. HG was sustained for 3 min at 50% of maximum voluntary contraction. ECG recording and measurement of blood pressure were made before, during, and after HG. During HG, systolic blood pressure was 188.7 +/- 3.4 mmHg (mean +/- SE) and diastolic blood pressure was 114.8 +/- 2.1 mmHg in hypertensives, while 145.3 +/- 2.6 mmHg and 93.8 +/- 1.1 mmHg in normals; the difference between hypertensives and normals was statistically significant (p less than 0.001). Incidence of HG-induced negative U-wave was 0% in normals, while 68.6% in hypertensives. In hypertensive subjects, HG-induced negative U-wave appeared in 24 of the 28 patients (85.7%) with minimum to moderate left ventricular hypertrophy shown by ECG and/or UCG findings (QRS-T angle greater than 130 degrees with left high voltage: left ventricular wall thickness greater than 12 mm). Further we recorded UCG during HG in 14 subjects. In 4 patients, negative U waves appeared simultaneously with increase in left ventricular dimension during diastole. In the remaining 10 cases that included both normals and hypertensives, however, neither increase in left ventricular end diastolic dimension nor negative U waves were observed. Thus we conclude that HG-induced negative U waves may be caused by stretch of the ventricular wall resulting from acute left ventricular volume overload.

Blood Pressure↗
PubMed1981

[Studies of interventricular septal motion after heart valve replacement by two-dimensional echocardiography and thallium 201 scintigraphy (author's transl)].

Etiology of abnormal interventricular septal motion detected by M-mode echocardiography after heart valve replacement was studied by two-dimensional echocardiography and thallium 201 scintigraphy in three patients with valvular heart disease (two with mitral regurgitation, and one with aortic regurgitation). M-mode and two-dimensional echocardiograms were recorded before and after heart valve replacement, using Aloka SSD-800. After intravenous injection of 2.0 mCi of ionic thallium 201, myocardial images were recorded with a scintillation camera (Searle PHO Gamma V) with converging collimator. Abnormal interventricular septal motion (systolic anterior motion) was observed echocardiographically in all of three patients after mitral or aortic valve replacement. Two-dimensional echocardiogram showed systolic anterior motion of the whole heart towards the anterior chest wall, though the left ventricle itself contracted normally. Thallium 201 scintigram showed no significant perfusion defects of the left ventricular wall including ventricular septum. No findings showing conduction disturbance, right ventricular volume overload or pericardial effusion were observed after heart valve replacement.

Adult↗
PubMed1981

[Digital image processing of the two-dimensional echocardiogram for the evaluation of regional contractility of the left ventricular wall (author's transl)].

Short-axis cross-sectional images of the left ventricle at the levels of the mitral valve, papillary muscles and apex were recorded on video tape by using a phased-array sector scanner. Endocardial and epicardial outlines of the cross-sectional left ventricular wall were determined automatically by a computer tracing process including digital image processing system. Short axis cross-sectional left ventricular walls of upper-, middle- and lower parts of the left ventricle were divided into eight segments, the center of gravity of end-diastolic left ventricular cavity being used as the reference point. Various parameters such as segmental radius, segmental wall thickness, cross-sectional area, left ventricular circumference and those changes during the cardiac cycle were determined in eight segments at three levels of the left ventricle. Regional contractility of the left ventricular wall was evaluated by systolic shortening of segmental radius and systolic thickening of segmental wall thickness. Contractility and pumping function of the overall left ventricle was assessed by shortening velocity of left ventricular circumference and fractional changes of cross-sectional area at three levels of the left ventricle. These were significantly and diffusely reduced in a patient with congestive cardiomyopathy (CCM), contrasting with a normal subject. Systolic changes in segmental radius and segmental wall thickness were significantly reduced in infarcted myocardium. Digital image processing system and segmental analysis of the left ventricular short-axis two-dimensional echocardiogram are very useful to evaluate the regional contractility of the left ventricle, quantitatively and automatically, especially in patients with myocardial disease including CCM and myocardial infarction with left ventricular asynergy.

Computers↗
PubMedDate not supplied

Percutaneous microwave coagulation therapy for unresectable hepatocellular carcinoma.

BACKGROUND/AIMS: Percutaneous microwave coagulation therapy (PMCT) has recently been introduced as a new treatment for hepatocellular carcinoma (HCC) in Japan. This study was performed to evaluate its efficacy and safety. METHODOLOGY: Thirteen patients with 17 nodules of unresectable HCC were subjected to PMCT under ultrasonic guidance. The tumors ranged from 1.2-4.4 cm in size. Assessment of the efficacy of PMCT was made by follow-up with dynamic computed tomography (CT). RESULTS: In the patients with small HCC (< or = 2.0 cm), 8 of 10 nodules (80%) showed complete remission after PMCT. In small nodules located on the liver surface, 3 out of 4 nodules (75%) showed complete remission. However, in the patients with larger HCC (> or = 2.1 cm), 5 out of 7 nodules developed local recurrence after PMCT. Regarding assessment of the necrotic area after PMCT, dynamic CT revealed enhancement that was possibly caused by congestion of the liver parenchyma surrounding the area of necrosis due to PMCT in the early phase of the treatment. Therefore, the necrotic area must be assessed carefully. Although a slight heat sensation and/or pain during microwave irradiation (a common effect of PMCT) occurred in all patients, there were no serious adverse effects. CONCLUSIONS: Complete remission of small HCC (< or = 2 cm in diameter) can be achieved with PMCT alone, but there seem to be limitations to its effectiveness with larger HCC (> or = 2.1 cm). There were no serious adverse effects from PMCT and the therapy can be safely carried out even in patients with poor liver function.

Aged↗